Abstract:
This long term experiment began in 1972. The experimental site is a tropical area, with a minimum annual temperature of 5.9 deg C, maximum annual temperature of 42.8 deg C, and mean annual rainfall of 1100 mm. The soil is characterized as Kheri series of fine montmorillonitic hyperthermic family of Typic Chromusterts (USDA). The soil properties are as follows:

Details of soil sampling method: Initial composite soil sample was collected from 0-25cm using a spade. After the layout of the experiment, 10-12 cores from each plot were sampled using a stainless steel auger following a zig-zag pattern as described by Jackson (1973) Soil Chemical Analysis. Printice-Hall of India Pvt Ltd., New Delhi, India. Subsequently, similar composite samples were drawn from each plot after each crop/annual cropping cycle.

Measurements made during this experiment are listed in the parameters section of this record. Time zero soil measurements were taken.

Description:
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There are at least 4 replicates in the experiment. The experiment has a randomized plot design. Bulk crop of maize fodder was grown in 2-3 seasons before laying out the experiment after selection of the site. Based on the ... fertility gradient (as far as possible), replications were assigned in such a way that all the treatments in one replication had more or less uniform fertility status. The treatments in each replication were allotted using random number selected from standard statistical text books. An absolute control plot (nil inputs). Also, many treatments can be regarded as tretaments for others.